What do you call the Horn part of the Horn?

My wife's horn is sounding pretty insipid, and when I opened the hood to have a look I found the plastic cover that directs the sound lying beneath the horn on top of the coolant lines. The edge that attaches this horn-shaped plastic piece to the horn has broken away and it needs to be replaced. This is as easy a fix as they get, and cheap too, but I have to figure out the answer to this question first --

What do you call the horn part of the horn?

I figured I'd search on "horn cover" and find the part in seconds, but that always takes me to the steering wheel on parts order pages. All the other searches I run want to sell me the entire horn instead of this little plastic piece.

Is this a standard size piece I can find at Pep Boys? Am I overthinking this? The piece likely costs $2.99.

I believe there are two horns-- a high pitch and a low pitch. The piece that is broken off, if I am not mistaken, is part of the horn assembly, so you will have to buy the entire horn, which will knock you back a good $50 per.

Or, you can go to any automotive online store and upgrade your horns; with prices ranging from about $30 and up for aftermarket single horns or kits.

Or, you could try repairing your existing horn-- if you have all the pieces, then glue or epoxy it back together.

Or try car-part.com for a good used one